The present invention relates generally to single-pole gas-insulated line ducts, and more particularly to a single-pole gas-insulated line duct with an enclosing tube and a tubular inner conductor held centered in place in the enclosing tube by support insulators, where the enclosing tube is divided into sections provided with flanges, and the inner conductor is also subdivided into sections connected together both mechanically and electrically.
DE-U-85 12 872 discloses this type of a single-pole gas-insulated line duct. Such an object can also be called a gas-insulated and single-phase metal-enclosed tubular gas-filled cable or also a gas-insulated busbar or tubular busbar. These ducts are used in applications having relatively short links between parts of a gas-insulated medium-voltage or high-voltage switching system erected at a mutual distance from one another, or between such a switching system and an associated transformer. The use of a line duct of the type indicated appears advantageous in comparison with the use of a high-voltage cable, in that a conventional cable requires bushings, the outer part of which is relatively long in regard to the lower insulation resistance of air. If the gas generally used for insulation of the plant sections, e.g. sulfur hexafluoride, is used this restriction does not apply, and short bushings of the known disk-shaped or star-shaped design are sufficient.
Since the structural design of the installation site of a switching system of the type mentioned can vary from case to case, it can be difficult to insert the line duct between the plant sections because the line duct is rigid in comparison with a cable.
The present invention is directed to the problem of developing components of a line duct from which the required gas-insulated link needed can be assembled in the simplest manner possible.